Currently, typically known magnetic sensors include a Hall sensor which harnesses the Hall effect, a magneto-resistance device, a magnetic transistor and other sensor. A current can be measured through detection of a magnetic flux generated by the current by means of any of the magnetic sensors as described. An example of conventional current sensors which have been widely used is illustrated in FIG. 1.
In FIG. 1, there are provided a magnetic core 100, a metal conductor 101 as a current path, a magnetic sensor 102, an amplifier 103, and an output terminal 104 of the amplifier 103.
However, the current sensor having this structure is difficult to be miniaturized since the magnetic core 100 for surrounding the metal conductor 101 through which current flows must be included. Moreover, the magnetic core 100 and the magnetic sensor 102 need to be separately manufactured before assembling those. This increases the manufacturing cost and makes it difficult to mass-produce the current sensor of this type.
Furthermore, the current sensor may be subject to magnetic noise coming through the gap of the magnetic core 100 in a lateral direction.